Medimop Medical Projects Ltd., Ra'anana, Israel (www.medimop.com) supply liquid drug transfer devices for use with medicinal vials containing liquid or powder drug contents and having a vial opening stopped by a typically rubber stopper. Vials are typically available in 13/14 mm and 20 mm standard sizes, and often contain expensive drugs. The liquid drug transfer devices include inter alia vial adapters with single lumen puncturing spikes, vented vial adapters with dual lumen puncturing spikes, fluid control devices illustrated and described in commonly owned PCT International Publication No. WO96/29113, MIX2VIAL® fluid control devices illustrated and described in commonly owned U.S. Pat. No. 6,558,365 to Zinger et al., in-line MIXJECT® fluid control devices illustrated and described in commonly owned PCT International Publication No. WO 2005/105014, and the like. The liquid drug transfer devices are used by both professional users and also home users, for example, young users, visually impaired users, infirm users, and the like, for self-drug administration purposes in the home.
The liquid drug transfer devices include a plastic molded vial adapter with a generally cylindrical skirt for telescopically slidingly receiving a vial opening therein, an integrally formed hollow puncturing spike for puncturing the vial's stopper and having at least one flow aperture towards the puncturing spike's tip for accessing the vial's interior, and at least one access port in flow communication with the puncturing spike. The skirts typically include four or six flex members including at least two non-adjacent vial retention flex members with at least partially circumferentially extending inwardly protruding vial retention ribs for snap fitting over a vial opening for vial retention purposes. The vial retention flex members are designed such that vial adapters cannot be released from a medicinal vial after being snap fitted thereon for sterilization purposes. Flex members not employed for vial retention purposes have smooth inner surfaces for bearing against a vial opening for stabilization purposes. Such vial stabilization flex members are typically of the same length as their counterpart vial retention flex members but maybe shorter, for example, as shown in US Patent Application Publication No. 2003/0199847 to Akerlund et al.
Misalignment of a liquid drug transfer device with respect to a vial results in puncturing difficulties and in some instances its vial adapter's puncturing spike's tip being embedded in the vial's stopper, thereby precluding flow communication with the vial's interior. In such instances, notwithstanding that a vial contains a full dosage of medicament, it is necessarily discarded. It has been long recognized that inaccurate snap fitting of vial adapters on vials can be at least partially contributed to a problematic design feature of medicinal vials described hereinafter. Professional users of liquid drug delivery devices are generally aware of this design feature but are still prone to inaccurately snap fit a vial adapter on a vial due to time pressure, and the like. Home users of liquid drug delivery devices are often not even aware of the design feature and are therefore even more prone to inaccurately snap fit a vial adapter on a vial despite their best efforts.